U.S. patent application number 09/906101 was filed with the patent office on 2001-11-29 for staggered low profile suspension.
Invention is credited to Smith, Earl Dallas.
Application Number | 20010045719 09/906101 |
Document ID | / |
Family ID | 27375492 |
Filed Date | 2001-11-29 |
United States Patent
Application |
20010045719 |
Kind Code |
A1 |
Smith, Earl Dallas |
November 29, 2001 |
Staggered low profile suspension
Abstract
A wheel suspension system including a wheel support pivotally
attached to a vehicle frame at two, laterally-spaced locations, the
wheel support being pivotal between an uppermost and a lowermost
position. The wheel support is biased to a position intermediate of
the uppermost and lowermost positions by a spring. The spring urges
apart a spring support of the wheel support from the vehicle frame,
the spring support being below the rotational axis of the wheel.
The pivotal axes of the pivotal attachments are located below the
rotational axis of the wheel.
Inventors: |
Smith, Earl Dallas;
(Greencastle, IN) |
Correspondence
Address: |
John V. Daniluck
Woodard, Emhardt, Naughton, Moriarty and McNett
Bank One Center/Tower
111 Monument Circle, Suite 3700
Indianapolis
IN
46204-5137
US
|
Family ID: |
27375492 |
Appl. No.: |
09/906101 |
Filed: |
July 16, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09906101 |
Jul 16, 2001 |
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09318428 |
May 25, 1999 |
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09318428 |
May 25, 1999 |
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09193501 |
Nov 17, 1998 |
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09193501 |
Nov 17, 1998 |
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08792972 |
Jan 31, 1997 |
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5839750 |
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60086899 |
May 27, 1998 |
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Current U.S.
Class: |
280/124.116 ;
180/210 |
Current CPC
Class: |
B60G 7/001 20130101;
B60G 2202/12 20130101; B60G 5/053 20130101; B60G 2200/132 20130101;
B60G 2202/152 20130101; B60G 3/145 20130101; B60G 2204/143
20130101; B60G 2300/38 20130101; B60G 3/14 20130101; B60G 2206/10
20130101; B60G 2202/112 20130101; B60G 11/113 20130101; B60G
2204/148 20130101; B60G 2300/04 20130101; B60G 11/28 20130101; B60G
2206/124 20130101; B60G 2204/13 20130101; B60G 2206/50 20130101;
B60G 15/12 20130101; B60G 2300/14 20130101; B60G 2204/1244
20130101 |
Class at
Publication: |
280/124.116 ;
180/210 |
International
Class: |
B62D 001/00; B62D
061/06 |
Claims
What is claimed is:
1. An apparatus for a vehicle frame comprising: a wheel; a wheel
support pivotally attached to the vehicle frame, said wheel support
being pivotable between a first position and a second position,
said wheel support rotatably supporting said wheel about a
rotational axis, said wheel support including an air spring
support; and an air spring biasing said wheel support to a position
between the first and second positions, said air spring urging said
wheel support apart from the vehicle frame, said wheel support
receiving said air spring in said air spring support, said air
spring being located below the rotational axis.
2. The apparatus of claim 1 wherein said wheel support is pivotable
about a pivot axis, and the pivot axis is located below the
rotational axis.
3. The apparatus of claim 1 wherein said wheel support is pivotable
about a pivot axis, and the pivot axis is parallel to the
rotational axis.
4. A wheel suspension for a vehicle frame comprising: a wheel
having a camber angle; and a wheel support coupled to the frame by
a first pivotal attachment and a second pivotal attachment and
pivotable about a pivot axis, said wheel support rotatably
supporting said wheel for rotation about a rotational axis; wherein
said first pivotal attachment is capable of being spaced apart from
said wheel support so as to adjust the camber angle of said wheel,
the rotational axis being located above the pivot axis.
5. The apparatus of claim 4 which further comprises: a shim
received between said first pivotal attachment and said wheel
support; and a fastener for releaseably coupling said first pivotal
attachment to the frame; wherein said shim spaces apart said first
pivotal attachment from said wheel support so as to adjust the
camber angle.
6. A wheel suspension for a vehicle frame comprising: a wheel
having a toe-in angle; and a wheel support coupled to the frame by
a first pivotal attachment and a second pivotal attachment and
pivotable about a pivot axis, said wheel support rotatably
supporting said wheel for rotation about a rotational axis; wherein
said first pivotal attachment is capable of being spaced apart from
said wheel support or from the frame so as to adjust the toe-in
angle of said wheel, the rotational axis being located above the
pivot axis.
7. The apparatus of claim 6 wherein the vehicle frame has a first
spring support disposed laterally inward of said wheel, said wheel
support has a second spring support below the rotational axis, and
further comprising a spring urging the first spring support apart
from the second spring support.
8. An apparatus comprising: a vehicle frame having a first spring
support and a cross member; a wheel; a wheel support pivotally
attached to the cross member, said wheel support being pivotable
between an uppermost position and a lowermost position about a
pivot axis, said wheel support rotatably supporting said wheel for
rotation about a rotational axis, said wheel support having a
second spring support, said cross member being lower than the
rotational axis; and a spring positioned between the first spring
support and the second spring support, said spring biasing said
wheel support to a position between the uppermost and lowermost
positions.
9. The apparatus of claim 8 wherein the second spring support is
below the rotational axis.
10. The apparatus of claim 9 wherein the first spring support is
below the rotational axis.
11. A wheel suspension system for a vehicle comprising: a frame
with a first spring support; a wheel; a wheel support pivotally
attached to said frame for pivoting about a pivot axis, said wheel
support having a second spring support, the second spring support
being located rearward of the pivot axis; means for rotatably
supporting said wheel on said wheel support, said wheel being
rotatable about a rotational axis; and a spring having an end and
being positioned between the first spring support and the second
spring support and urging the first spring support apart from the
second spring support, the second spring support being located
below the rotational axis and laterally inward from said wheel, the
end of said spring being between the second spring support and the
rotational axis.
12. The apparatus of claim 11 wherein the first spring support is
located generally at or below the rotational axis.
13. A wheel suspension system for a vehicle comprising: a frame
having a transverse structure; a wheel; a wheel support coupled to
the transverse structure by first and second pivotal attachments
and pivotable between an uppermost position and a lowermost
position, said wheel support rotatably supporting said wheel for
rotation about a rotational axis, said first and second pivotal
attachments being located forward of said rotational axis; and a
spring biasing said wheel support to a position between the
uppermost and lowermost positions, said spring being coupled to
said wheel support below the rotational axis, said spring being
coupled to the transverse structure, the transverse structure
defining a plane that is at or below the rotational axis.
14. The apparatus of claim 13 wherein said wheel support couples to
said spring laterally inward from said wheel.
15. A suspension system for a vehicle, comprising: a frame; a
wheel; a wheel support pivotally attached to said frame and pivotal
about a pivot axis, said wheel support rotatably supporting said
wheel about a rotational axis, the pivot axis being located below
the rotational axis; an air spring positioned between said frame
and said wheel support; a source of compressed air; and a valve
operably coupled to said source and said air spring and capable of
placing said air spring in fluid communication with said source or
in fluid communication with ambient air; wherein said valve places
said air spring in fluid communication with said source or with
ambient air in response to pivoting of said wheel support.
16. The apparatus of claim 15 wherein said wheel is rotatable about
a rotational axis, and said air spring is located below the
rotational axis.
17. A wheel suspension system for a vehicle comprising: a wheel
rotatable about a rotational axis; a frame with a transverse
structure, the transverse structure being below the rotational
axis; a wheel support pivotally attached to the transverse
structure and pivotable about a pivot axis between an uppermost
position and a lowermost position, said wheel support rotatably
supporting said wheel, the pivot axis being below the rotational
axis; a spring coupled to said frame and coupled to said wheel
support for biasing said wheel support to a position intermediate
of the uppermost and lowermost positions; and a shock absorber for
dampening the motion of said wheel support, said shock absorber
having two ends, one of the ends of said shock absorber being
coupled to the transverse structure, said shock absorber being
located substantially below the rotational axis.
18. The apparatus of claim 17 which further comprises a lever arm
pivotally attached to said frame, said lever arm having two ends,
one end of said lever arm being coupled to said wheel support, the
other end of said lever arm being coupled to the other end of said
shock absorber.
19. The apparatus of claim 17 wherein said shock absorber has an
axis about which said shock absorber is actuated, and the axis is
generally horizontal.
20. A wheel suspension system for a vehicle, comprising: a trailer
frame with two opposite sides, said trailer frame having a
longitudinal axis; a first wheel supporting said trailer frame from
a roadway, said first wheel having a first rotational axis, said
first wheel being located on a first side of said trailer frame,
said first wheel being rotatably supported about said first
rotational axis by a first wheel support, said first wheel support
being pivotally attached to said trailer frame below said first
rotational axis; a second wheel supporting said trailer frame from
the roadway, said second wheel having a second rotational axis,
said second wheel being located on the first side of said trailer
frame and spaced longitudinally aft of said first wheel, said
second wheel being rotatably supported about said second rotational
axis by a second wheel support, said second wheel support being
pivotally attached to said trailer frame below said second
rotational axis; and a third wheel supporting said trailer frame
from the roadway, said third wheel having a third rotational axis,
said third wheel being located on a second side of said trailer
frame, said third wheel being rotatably supported about said third
rotational axis by a third wheel support, said third wheel support
being pivotally attached to said trailer frame below said third
rotational axis; wherein said third rotational axis is spaced
longitudinally apart from said first rotational axis and said
second rotational axis.
21. The apparatus of claim 20, wherein said third axis is spaced
longitudinally aft of said first axis and longitudinally forward of
said second axis.
22. The apparatus of claim 20 wherein said first wheel support
includes an air spring support, and which further comprises a first
air spring being received within said air spring support, said
first air spring being located below the first rotational axis.
23. A wheel suspension system for a vehicle, comprising: a trailer
frame with two opposite sides, said trailer frame having a
longitudinal axis; a first wheel supporting said trailer frame from
a roadway, said first wheel being located on a first side of said
trailer frame, said first wheel being rotatably supported about a
first rotational axis of a first wheel support, said first wheel
support being pivotally attached to said trailer frame below said
first rotational axis; and a second wheel supporting said trailer
frame from the roadway, said second wheel being located on the
second side of said trailer frame and spaced longitudinally aft of
said first wheel, said second wheel being rotatably supported about
a second rotational axis of a second wheel support, said second
wheel support being pivotally attached to said trailer frame below
said second rotational axis; wherein said first rotational axis is
not coincident with the rotational axis of any other wheel
supporting said trailer frame, and said second rotational axis is
not coincident with the rotational axis of any other wheel
supporting said trailer frame.
24. A wheel suspension system for a vehicle comprising: a frame
with a first portion and a second portion; a first wheel; a second
wheel; a first wheel support pivotally attached to said frame for
pivoting about a first pivot axis, said first wheel support
rotatably supporting said first wheel about a first rotational
axis, said first wheel support having a first spring support, said
first spring support being located rearward of the first pivot
axis; a second wheel support pivotally attached to said frame for
pivoting about a second pivot axis, said second wheel support
rotatably supporting said second wheel about a second rotational
axis, said second wheel support having a second spring support,
said second spring support being located forward of the second
pivot axis; a first spring for urging said first wheel support
apart from a first portion of said frame, said first spring having
an end coupled to the first portion below the rotational axis; and
a second spring for urging said second wheel support apart from a
second portion of said frame, said second spring having an end
coupled to the second portion below the rotational axis.
25. The apparatus of claim 24 wherein said frame has two, generally
opposed sides and said first wheel is on one side of said frame and
said second wheel is on the other side of said frame.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 09/318,428, filed May 25, 1999, which is a
continuation-in-part of U.S. patent application Ser. No.
09/193,501, filed Nov. 17, 1998, entitled LEAF SPRING WHEEL
SUSPENSION SYSTEM, (now abandoned), which is a continuation of U.S.
patent application Ser. No. 08/792,972, filed Jan. 31, 1997,
entitled LEAF SPRING WHEEL SUSPENSION SYSTEM, which issued as U.S.
Pat. No. 5,839,750 on Nov. 24, 1998. This application claims
priority to U.S. provisional patent application Serial No.
60/086,899, filed May 27, 1998. All of the above-referenced
applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] This invention relates to the field of wheel suspensions,
and particularly to wheel suspension systems that independently
support the wheels of a vehicle in which a wide and low cargo floor
is desired. This invention is an improvement to the wheel
suspension systems described in my earlier patents, namely, U.S.
Pat. No. 4,878,691, issued on Nov. 7, 1989, U.S. Pat. No.
4,934,733, issued on Jun. 19, 1990, U.S. Pat. No. 5,016,912, issued
on May 21, 1991, and U.S. Pat. No. 5,275,430, issued on Jan. 4,
1994, all incorporated herein by reference.
[0003] For a variety of reasons, it is frequently desirable to have
the cargo floor of a trailer, van, or similar vehicle as low as
reasonably possible. A low floor provides for more efficient
transportation of cargo, giving a vehicle more useable, internal
space for given exterior dimensions. Also, a low floor placed close
to the road surface makes for easier access to the vehicle. These
and other advantages of a low cargo floor have motivated various
proposals for low vehicle floors.
[0004] In U.S. Pat. No. 4,032,167, there is disclosed a trailer for
transporting motorcycles. This trailer includes wheels mounted to
fixed spindles that are bolted to a rigid frame. Because of this
rigid attachment, considerable forces are imparted to the frame.
Further, rigidly fixed wheels will have undesirable effects on the
handling and ride comfort of a vehicle.
[0005] In another type of suspension system, the vehicle is
supported on a through axle that extends the width of the vehicle
below the vehicle frame. Examples of this are found in U.S. Pat.
Nos. 4,580,798 and 4,615,539. Because the axle extends the entire
width of the vehicle, the cargo space of the vehicle must be
adapted to fit over the axle. Thus, the axle and the diameter of
the wheel establish the height of the cargo floor above the
ground.
[0006] In a different type of wheel suspension system, the through
axle extending the width of the vehicle is replaced with short,
independent axles present only at the sides of the vehicle. An
example of this is shown in U.S. Pat. No. 4,666,181. This short
independent axle is attached to a support arm, which is pivotably
attached to the vehicle frame. With this type of suspension, the
axle and wheel diameter no longer create a minimum height for the
vehicle cargo floor. Other considerations, such as ground
clearance, establish the height of the cargo floor. The suspension
system components reside in or around the wheel well. This area
around the wheel well, however, still represents limitations to the
cargo area. Further compaction of the wheel suspension system will
result in more efficient and convenient use of cargo space.
SUMMARY OF THE INVENTION
[0007] Briefly describing one aspect of the present invention there
is provided an apparatus comprising a wheel, a wheel support, and
an air spring. The wheel support is pivotally attached to the
vehicle frame and is pivotable between a first position and a
second position. The wheel support rotatably supports the wheel by
the rotational axis. The wheel support includes an air spring
support. The air spring urges the wheel support apart from the
vehicle frame. The wheel support receives the air spring in the air
spring support. The air spring support is located below the
rotational axis. The wheel support may be of the trailing-arm type,
in which the rotational axis is rearward of the pivot axis, or the
leading-arm type, in which the rotational axis is forward of the
pivot axis.
[0008] Briefly describing another aspect of the present invention,
a wheel support is coupled to the frame by a pivotal attachment
which permits adjustment of the camber angle of the wheel. Another
aspect of the present invention concerns a wheel support that is
pivotally coupled to a frame such that the pivotal attachment
permits adjustment of the toe-in angle of the wheel. In another
aspect of the present invention, a wheel support is pivotally
attached to a cross-member of a frame, the cross-member being lower
than the rotational axis of the wheel. In another aspect of the
present invention, a wheel support is coupled to a transfer
structure by first and second pivotal attachments that are located
forward of the rotational axis. A spring is coupled to the wheel
support below the rotational axis, and is also coupled to the
transfer structure. Yet another aspect of the present invention
includes a wheel support with a pivot axis located below the
rotational axis. An air spring positioned between the frame and the
wheel support is operably coupled to a source of compressed air.
Another aspect of the present invention includes a wheel support
pivotally attached to a frame, and a shock absorber for dampening
motion of the wheel support, the shock absorber being located
substantially below the rotational axis of the wheel. In yet
another aspect of the present invention, there is a vehicle with
multiple wheels for supporting the vehicle from the ground. The
wheels are arranged on either side of the vehicle, such that the
rotational axes of the wheels are not coincident.
[0009] These and other aspects of the present invention will be
apparent from the following description of the preferred
embodiment, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a perspective view of a pair of wheel suspension
systems constructed in accordance with one embodiment of the
present invention.
[0011] FIG. 2 is a side elevational view of the wheel assemblies
and wheels of FIG. 1 mounted to a vehicle frame, viewing outwardly
from inboard of the assemblies.
[0012] FIG. 3 is a top plan view of the wheel assemblies of FIG.
1.
[0013] FIG. 4 is a side elevational view of a frame and suspension
section of a vehicle according to another embodiment of the present
invention.
[0014] FIG. 5 is a top plan view of the vehicle section of FIG. 4
as taken along line 5-5 of FIG. 4.
[0015] FIG. 6A is a cross-sectional view of the vehicle section of
FIG. 5 as taken along line 6-6 of FIG. 5.
[0016] FIG. 6B shows the vehicle section of FIG. 6A supporting a
cargo compartment.
[0017] FIG. 7 is a partial cross-sectional view of a portion of the
vehicle section of FIG. 5 as taken along the line 7-7 of FIG.
5.
[0018] FIG. 8A is a side elevational view of a wheel support and a
portion of the vehicle section of FIG. 5 as viewed along line 8A-8A
of FIG. 5.
[0019] FIG. 8B is a side elevational view of the wheel support and
portion of the vehicle section of FIG. 8A including a reinforcing
doubler.
[0020] FIG. 9 is a perspective view of a wheel support according to
one embodiment of the present invention.
[0021] FIG. 10A is a side elevational view of a pivotal attachment
according to one embodiment of the present invention.
[0022] FIG. 10B is a side elevational view of another pivotal
attachment according to one embodiment of the present
invention.
[0023] FIG. 11 is an enlargement of the area within dotted oval 189
of FIG. 5.
[0024] FIG. 12 is a perspective view of a two-wheeled embodiment of
the present invention as used within a van.
[0025] FIG. 13 is a perspective view of a four-wheeled embodiment
of the present invention as used within a trailer.
[0026] FIG. 14 is a top plan view of a vehicle section in
accordance with another embodiment of the present invention.
[0027] FIG. 15 is a partial side view of the vehicle section of
FIG. 14 as taken along line 15-15 of FIG. 14.
[0028] FIG. 16 is a top plan view of a vehicle section in
accordance with another embodiment of the present invention.
[0029] FIG. 17 is a top plan view of a wheel support according to
one embodiment of the present invention.
[0030] FIG. 18 is a side elevational view of the wheel support of
FIG. 17.
[0031] FIG. 19 is a cross-sectional, perspective view of another
embodiment of the present invention.
[0032] FIG. 20 is a top plan view of a frame and suspension system
according to another embodiment of the present invention.
[0033] FIG. 21 is a top plan view of a frame and suspension system
according to another embodiment of the present invention.
[0034] FIG. 22 is a top plan view of a frame and suspension system
according to another embodiment of the present invention.
[0035] FIG. 23 is a top plan view of a frame and suspension system
according to another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] For the purposes of promoting an understanding of the
principles of the invention, reference will now be made to the
embodiment illustrated in the drawings and specific language will
be used to describe the same. It will nevertheless be understood
that no limitation of the scope of the invention is thereby
intended, such alterations and further modifications in the
illustrated device, and such further applications of the principles
of the invention as illustrated therein being contemplated as would
normally occur to one skilled in the art to which the invention
relates.
[0037] The present invention provides a wheel suspension system
which has an extremely low profile. The suspension system utilizes
a wheel support that is connected with the vehicle frame at points
of attachment on the frame which are spaced apart laterally,
thereby providing lateral support for the wheel. The wheel support
is pivotable between an uppermost position and a lowermost
position. One or two biasing means are included to maintain the
wheel support in an intermediate position and to absorb loads from
the wheel.
[0038] Referring in particular to FIG. 1, there is shown a wheel
suspension system constructed in accordance with the present
invention. The system includes a pair of wheels mounted to a
vehicle frame by respective wheel supports. The wheel supports are
maintained in position by a leaf spring secured between the wheel
support and the frame.
[0039] The two wheels are shown mounted on the same side of the
vehicle, and of course similar wheels and suspension systems are
used on the opposite side of the vehicle. It will further be
appreciated that the present invention is equally useful when only
one wheel is supported on each side of the vehicle. Also, the
embodiment of FIG. 1 utilizes a single leaf spring, but could
equally use separate biasing means serving the function of the
spring.
[0040] The wheels are attached to cross members of the vehicle
frame by wheel supports. The wheel supports attach to the cross
member at a pair of pivot points, with one pivot point being
inboard of the other pivot point. This lateral displacement of one
pivot point relative to the other promotes the lateral stability of
the wheel support. The frame cross members are held in position by
a longitudinal member of the frame.
[0041] The wheel support connects to the frame cross member on a
portion of the support that is largely horizontal and parallel to
the roadway. The wheel support also has a section that is largely
vertical relative to the roadway, to which the wheel, spring and
shock absorber are attached. The spring and shock absorber attach
to the vertical portion of the wheel support and also a vertical
member of the frame. The upright portion of the wheel support is
adaptable to springs such as the coil type, air bag type, or any
other type of spring that creates a spring force when its
attachment points are displaced relative to each other.
[0042] There is an additional spring that acts between the wheel
support and the frame. This spring is of the leaf type, and
attaches to both the horizontal portion of the wheel support and
also to the frame. In a preferred embodiment, the attachment of the
spring to the wheel support permits relative sliding of the spring
within the wheel support in the fore and aft directions, but
otherwise transmits spring forces created by the pivoting of the
wheel support relative to the frame cross member. Alternative
attachments of the leaf spring may be used, including an attachment
by which one end of the spring is secured to a wheel support and
the portion connected with the vehicle frame is allowed to slide
relative thereto. Additionally, a spring configuration and
attachment could be employed in which all attachments of the spring
prevent or allow for sliding movement.
[0043] It is a feature of the leaf spring design that a biasing
device is provided that fits generally within the typical vehicle
frame. The leaf spring is located interior of the frame perimeter.
It is also positioned below the upper surface of the frame, and
thereby does not intrude into space available above the frame for
the bed of the vehicle, e.g., the floor of a trailer or van. As
shown in FIG. 1, the leaf spring is conveniently received through
an opening in a frame member, thus accommodating the position of
the leaf spring and minimizing the space required for the
spring.
[0044] This leaf spring may be used simultaneously with adjacent
wheels. The spring can attach, slidably or not, to two wheel
supports and also be attached to a cross member of the frame
in-between the two wheel supports.
[0045] The present invention provides a wheel suspension system
useful in a variety of applications. The preferred embodiment is
characterized by a wheel support with a largely vertical portion
and a largely horizontal portion. The vertical portion is generally
outboard of the vehicle frame. The horizontal portion is below or
within much of the vehicle frame. Also, the shock absorber and
springs of the preferred embodiment are similarly situated either
outboard of much of the vehicle frame, or below or within much of
the vehicle frame. This general arrangement permits maximum
utilization of the area inboard and above most of the frame as
useful cargo area. The wheel suspension system is useful, for
example, for mounting the wheels of a trailer, or for the rear
wheels of a front-wheel drive vehicle, such as a van.
[0046] Referring in particular to FIG. 1, there is depicted a
preferred embodiment of the present invention in a perspective
view. Frame outboard longitudinal member 2, shown with an "L" cross
section, is a major structural member of the vehicle frame
traversing fore and aft along one side of the vehicle and defining
an outer perimeter of the frame. Attached to it are frame cross
members 4 and 6, located fore and aft of each other, respectively.
These cross members traverse the width of the vehicle, and
typically terminate at the mirror image wheel suspension system on
the other side of the vehicle frame. The frame cross members
include frame vertical members 5 and 7, respectively, located
outboard of longitudinal member 2.
[0047] Wheel suspension systems according to the present invention
are mounted to the vehicle frame in the following manner. The wheel
suspension systems include, for example, wheel supports 24 and 26.
The supports carry stub axles or the like to support wheels
thereon. In turn, the wheel supports are mounted to the vehicle
frame for pivoting about a horizontal axis, thereby allowing the
carried wheel to move up and down with respect to the vehicle
frame.
[0048] Located just aft of the cross members are wheels 8 and 10.
These wheels are attached to the wheel supports 24 and 26,
respectively, and are free to rotate about respective hubs. For
example, wheel 8 is mounted to hub 16 and is free to rotate about a
horizontal axis 12 (FIG. 3). This hub is attached to upright
portion 20 of wheel support 24.
[0049] The wheel support further includes means for attaching
pivotally to the vehicle frame. The support preferably has a
generally flat, horizontal portion 21 attached pivotally to frame
cross member 4 at inboard pivotal attachment 28 and outboard
pivotal attachment 30. The attachments preferably comprise a
bracket secured to the frame, and a bolt and nut received through
apertures in the bracket and the associated portion of the wheel
support. These two pivotal attachments are aligned to provide for
pivoting about a horizontal axis extending therethrough. The
pivotal attachments are also displaced laterally to enhance the
lateral stability of the wheel support, and therefore of the first
wheel 8.
[0050] A similar method is used to attach wheel 10 to frame cross
member 6. Hub 18, about which second wheel 10 is free to rotate, is
attached to upright portion 22 of wheel support 26. This wheel
support further includes a horizontal portion 23 which is pivotally
attached to frame cross member 6 at pivotal attachments 32 and 34.
The wheel support 26 is thereby pivotal with respect to the frame
about a horizontal axis extending through the pivotal attachments
32 and 34, and the wheel 10 is rotatable about an axis 14 (FIG. 3)
which extends parallel to the pivoting axis.
[0051] The upright portions of the wheel supports attach not only
to the hubs, but also continue around the forward upper quadrant of
the respective wheels and attach to spring and shock absorber
assemblies. As shown in FIGS. 2 and 3, air spring (air bag) 50 and
shock absorber 56 both connect support upright portion 20 to frame
vertical member 5. Air spring 50 is attached at face 51 of first
wheel support 24, and also at face 52 of first frame vertical
member 5, in conventional fashion. Shock absorber 56 is mounted in
a typical manner along side air spring 50, to first wheel support
24 at pivotal attachment 57, and to first frame vertical member 5
at pivotal attachment 58. As wheel support 24 rotates about pivots
28 and 30, the distance between upright portion 20 and vertical
member 5 changes. The air bag and shock absorber accommodate this
movement and cushion the pivoting of the wheel support.
[0052] An alternate to the spring and shock absorber arrangement
utilizes a coil spring 60, as shown attached between wheel support
26 and frame vertical member 7 in conventional fashion. This spring
attaches to front spring mount 62 of vertical member 7, and to rear
spring mount 61 of wheel support 26. When utilizing a coil spring,
the shock absorber could be attached alongside the spring, similar
to the positioning shown for shock absorber 56, or it could be
attached coaxially with the coil spring. Shock absorber 66 is shown
mounted between frame vertical member 7 and wheel support 26 inside
the coils of coil spring 60.
[0053] Additionally spring support for the wheel occurs in respect
to the horizontal portions of the wheel support members. The
horizontal portion is configured to be substantially flat and to
underlie the vehicle frame. It is a feature of the present
invention that such a compact wheel support is also supportable in
a manner to further enhance the low profile of the overall
suspension in comparison to the vehicle frame.
[0054] The wheel support engages a leaf spring 70 that is secured
between the support and the vehicle frame. Each wheel support can
be combined with an individual leaf spring. Alternatively, pairs of
wheel supports can be accommodated by a single leaf spring, as
shown in the drawings. In general, a wheel support includes a leaf
spring receiving member for connection with an end of the leaf
spring. Leaf spring 70 is shown having a forward portion received
within a narrow slot comprising a leaf spring forward attachment
78. Leaf spring 70 continues in the aft direction, attaching to the
frame by means of the frame attachment 74 through which it passes.
Aft of that location the leaf spring includes a portion received
within the rear attachment 72 defined by the wheel support 26.
[0055] Frame attachment 74 prevents lateral, longitudinal or
vertical motion of the leaf spring at the point of attachment.
However, pivoting is permitted about the lateral access established
by frame attachment 74.
[0056] As wheel support 24 pivots about the axis defined by the
attachments 28 and 30, forward attachment 78 of the wheel support
moves in an arc relative to cross member 4. The distance between
attachments 74 and 78 changes as the wheel support pivots.
Attachment 78 permits sliding of leaf spring 70 in the fore and aft
directions. Thus, a change in the fore/aft distance between
attachments 74 and 78 does not result in the creation of spring
load from spring 70. However, attachment 78 does resist any change
in the vertical distance between attachments 78 and 74. Thus,
rotation of the wheel support results in a change in spring load of
spring 70 for the vertical component of movement.
[0057] Although the preferred embodiment depicts a single leaf
spring attached near its center in providing support to wheel
supports both in front and behind it, it is also possible to use a
single leaf spring for each wheel support. For example, it would be
possible to remove all portions of leaf spring 70 aft of attachment
74, and have the remainder support only first wheel support 24.
Similarly, it would also be possible to remove all portions of leaf
spring 70 forward of attachment 74, thus providing support only to
second wheel support 26. Thus, leaf spring 70 could provide
independent support for each wheel support, and the attachment of
that independent leaf spring, could either be forward or aft of the
respective wheel rotational axis.
[0058] Alternate embodiments of the present invention shown in
FIGS. 4-18 also provide a wheel suspension system which has an
extremely low profile. These alternate embodiments utilize a wheel
support that is connected by a pair of pivotal attachments to the
vehicle frame. The wheel support supports a wheel for rotation
about a rotational axis. The rotational axis is located above the
pivotal attachments and above the transverse frame structure which
lowers the profile of the wheel support and permits additional
cargo-carrying volume above the wheel support. The pivotal
attachments are spaced apart laterally, thereby providing lateral
support for the wheel. The wheel support is pivotal between a
first, uppermost position and a second, lowermost position. The
pivot axes of the two pivotal attachments are generally coincident,
and are preferably arranged such that the wheel support pivots in a
pitching direction relative to the vehicle.
[0059] Some of these embodiments incorporate a spring such as an
airbag, leaf spring, or coil spring for biasing the wheel support
to a position intermediate of the first and second positions. The
spring is placed between a spring support of the vehicle frame and
a spring support of the wheel support, and is placed beneath the
rotational axis of the wheel and preferably inward of the wheel and
tire. This placement of the spring helps increase useable cargo
carrying volume for the vehicle and simplifies the structural
support necessary to support the biasing loads by utilizing planar
portions of the vehicle frame to support the spring. In addition,
some embodiments orient the shock absorber in a generally
horizontal position beneath the rotational axis of the wheel. This
placement of the shock simplifies the structure of the wheel
support and also the upright structures of the frame that houses
the wheels. In some of those embodiments with horizontal shock
absorbers placed below the wheel rotational axis, the biasing
mechanism includes either an air bag, or one or more leaf springs
coupled to both a wheel support and a cross member of the vehicle
frame. In yet other embodiments, a leaf spring couples to adjacent
wheel supports and to the vehicle frame.
[0060] Referring to FIGS. 4-6, a vehicle frame and suspension
section 98 with a longitudinal axis X includes a wheel support 100
which rotatably supports a wheel 102 and tire 104. Wheel support
100 is pivotally attached to a cross member 106 of a transverse
frame structure 116 by a first pivotal attachment 108 and a second
pivotal attachment 110. Pivotal attachments 108 and 110 couple
wheel support 100 to frame section 98, and are displaced laterally
from one another so as to provide stability to wheel support 100.
Pivotal attachments 108 and 110 are pivotal about first axis 109
and second axis 111, respectively. Pivotal axes 109 and 111 are
preferably coincident with each other and are preferably oriented
transverse to the direction of motion of the vehicle. Wheel support
100 is thus pivotally attached so as to permit pitching motion of
wheel support 100. Wheel support 100 includes a generally upright
portion 112 which supports a spindle, or stub axle, 114 about which
wheel 102 rotates. The present invention contemplates spindles,
hubs, stub axles, and other similar devices known to those of
ordinary skill in the art as means for rotatably supporting a wheel
on the wheel support.
[0061] Frame and suspension section 98 includes a row of tires 104
on either side of a transverse frame structure 116. Transverse
frame structure 116 generally supports the vehicle cargo or utility
section directly above it, as best seen in FIGS. 12 and 13.
Referring again to FIGS. 5 and 6A, transverse frame structure 116
includes laterally disposed transverse frame sides 118 and 120.
Attached to first transverse frame side 118 is a first upright
frame structure 122. Attached to second transverse frame side 120
is a second upright frame structure 124. Frame structures 124, 116,
and 122 form a generally U shape, as best seen in FIG. 6A, with
transverse structure 116 being attached to the bottoms of the
opposing upright frame structures 124 and 122. The top surface of
transverse structure 116 preferably defines a plane that is located
generally at or below the rotational axis of the wheels.
[0062] Wheels 102, shock absorbers 136, spindles 114, and upright
portion 112 of wheel support 100 are disposed within upright
structures 122 and 124. Spindle 114 supports one or more wheels 102
disposed within the upright frame structures. Spindle, or stub
axle, 114 is not an axle that extends across transverse frame
structure 116. By not having an axle spanning between upright frame
structures 122 and 124, it is possible to have more cargo-carrying
volume within the vehicle. Transverse frame structure 116 can thus
be located below the rotational axes of the wheels 102, and cargo
can be carried below the rotational axes also.
[0063] Transverse frame structure 116 preferably includes a cross
member 106 for each pair of wheel supports 100. Cross members 106
are attached to longitudinal members 126 and sides 120 and 118 by
corner reinforcements 128. In addition, longitudinal members 126
are also interconnected to members 106 preferably with
reinforcements 130. Frame spring supports 132 of transverse frame
structure 116 are generally planar portions in one embodiment which
extend inward preferably from either first side 118 or second side
120 to longitudinal members 126. Preferably, spring supports 132
are laterally disposed inwardly from the wheel being supported.
Portions of wheel supports 100 for supporting a spring are located
below frame spring supports 132. Disposed between each wheel
support 100 and frame spring support 132 in one embodiment is an
air spring 133. Frame spring support 132 provides a support for air
spring 133.
[0064] Although what has been shown and described is a specific
arrangement of cross members and longitudinal members with
reinforcements, the present invention also contemplates other
arrangements for a transverse frame structure as would be known to
one of ordinary skill in the art. Although welding is a preferable
means of joining various members of frame and suspension section
98, the present invention also contemplates other joining and
integrating methods, including fusion, bonding, brazing, bolting,
casting, molding, and similar methods known in the art. Also, those
of ordinary skill in the art will recognize that the cross members
and longitudinal members can have a variety of cross sectional
shapes, such as for C channels, I beams, L shapes, rectangular
shapes, and others.
[0065] Wheel support 100 is pivotally attached to cross member 106
by a pair of pivotal supports 108 and 10. Supports 108 and 10
permit pivoting of wheel support 100 in a pitching direction about
a pivotal axis that coincides with first axis 109 of support 108
and second axis 111 of support 110. Inboard pivotal attachment
member 180 of support 100 is preferable releasably fastened to
inner pivot 108a of support 108. Inner pivot 108a is coupled to
outer support housing 108c through a rubber bushing 108b. Inner
pivot 108a is able to pivot relative to housing 108c by twisting
rubber bushings 108b. In a similar fashion, an inner pivot 110a of
pivotal attachment member 110 is able to pivot relative to the
housing 110c by twisting a rubber bushing 110b.
[0066] Wheel support 100 supports a wheel for rotation about a
rotational axis 158, and is arranged and constructed such that
there is usable cargo volume below the rotational axis of the
wheel, as best seen in FIGS. 6A, 12, and 13. Horizontal portion 168
of wheel support 100 lies generally below the volume useful for
cargo. Pivotal attachments 108 and 110, which pivotally support
wheel support 100, have pivot axes 109 and 111, respectively, that
are located below rotational axis 158. In one embodiment of the
present invention, pivot axes 109 and 111 are preferably parallel
to rotational axis 158, as best seen in FIG. 8A.
[0067] Wheel support 100 pivots about pivot axis 109 and 111 in a
pitching direction relative to the vehicle, and is pivotal between
an uppermost position and a lowermost position. Wheel support 100
is biased to a position between the uppermost and lowermost
positions, preferably by air spring 133. However, the present
invention also contemplates the use of other means for biasing the
wheel support, including by way of example one or more coil springs
or one or more leaf springs. The one or more springs bias wheel
support 100 to a position between the uppermost and lowermost
positions by urging spring support 156 of wheel support 100 apart
from frame spring support 132 of the vehicle frame.
[0068] In one embodiment, spring supports 156 and 132 generally
face each other and are part of a structural load path for the
spring forces from spring 133. Preferably, spring supports 156 and
132 are disposed laterally inward from the wheel being supported,
although the present invention also contemplates spring supports
disposed laterally inward from the tire being supported. Spring
supports 156 and 132 are preferably generally planar in those
embodiments utilizing air springs with planar attachment surfaces.
However, the present invention also contemplates those embodiments
in which spring supports 156 and 132 are constructed and arranged
to compatibly support other types springs, including, for example,
leaf springs and coil springs.
[0069] Referring to FIG. 7, upright frame 124 is joined to
transverse frame structure 116 along second side 120 of frame
structure 116. In one embodiment, vertical wall section 144 of
upright structure 124 is angled outwardly about 4 degrees from the
vertical, so as to permit additional cargo space. Wall section 144
is preferably fused to a longitudinal member 150 in the shape of a
C channel that extends along side 120.
[0070] Air spring 133 is preferably fastened to attachment plate
152 by fasteners (not shown) along upper contact face 154a of air
spring 133, contact face 154a being one end of air spring 133.
Attachment plate 152 is preferably fastened to spring support 132
of frame section 116 by fasteners (not shown). One side of spring
support 132 is preferably welded to a longitudinal member at 126,
and the other side of spring support 132 is preferably welded to
longitudinal member 150, the present invention contemplating other
means known to those of ordinary skill in the art for coupling the
spring support to the transverse fame section.
[0071] Air spring 133 is preferably fastened by fasteners (not
shown) to spring support 156 of wheel support 100 along a lower
contact face 154b of air spring 133, contact face 154b being the
other end of air spring 133, this end of air spring 133 being
between the second spring support 156 and the rotational axis of
the wheel. Thus, upper contact face 154a is coupled to and in
contact with a first spring support 132 and lower contact face 154b
is coupled to and in contact with a second spring support 156.
[0072] Although it is preferable to couple lower face 154b of the
air spring with fasteners to attachment member at 156, coupling is
not necessary provided lower face 154b is in contact with spring
support 156. Attachment members 156 and 132 support biasing loads
from spring 133.
[0073] Upright portion 112 of wheel support 100 supports spindle
114. Spindle 114 is attached at a fastener attachment pattern 160
to upright portion 112. Spindle 114 defines a rotational axis 158
that is generally horizontal and preferably parallel to the pivotal
axis of wheel support 100. However, the present invention also
contemplates those embodiments in which the rotational axis of the
wheel and the pivotal axis of the wheel support are not parallel. A
hub 162 is mounted to spindle 114 by a pair of bearings 163. A
brake drum 164 is fastened to hub 162, and provides a braking
surface for a pair of brake shoes 166.
[0074] Upright portion 112 of wheel support 100 in one embodiment
includes a support structure 134. A shock absorber 136 is pivotally
coupled to support structure 134 by a coupling end 138 that
attaches to ears 140 of support structure 134. Attachment ears 140
for coupling to shock absorbers 136 are attached to support plate
structure 183 of support structure 134 as best seen in FIGS. 8A and
8B. As seen in FIGS. 6A-7, the other coupling end 142 of shock
absorber 136 is pivotally coupled within upright frame structures
124 and 122. Shock absorber 136 and support structure 134 are
located forward of the rotational axis of wheel 102, and above the
pivot axis of wheel support 100 in some embodiments.
[0075] Support structure 134 preferably provides features for
attachment of various components, including braking system
components (not shown). As best seen in FIG. 9, support 134
includes support plates 183 which incorporate fastening patterns
182 and 184 for support and attachment of various components,
including braking system components (not shown). Top support plate
183 also defines a slot 186 through which brake system linkages
(not shown) pass onto the braking system components for wheel
102.
[0076] Referring to FIG. 8A, a side elevational view of wheel
support 100 and a portion of frame 116 is shown. Some embodiments
of wheel support 100 include a stiffening member 167 generally in
the shape of a "W" to provide stiffness and strength along spring
support 156 and to better distribute loads from air spring 133 into
wheel support 100. However, the present invention also contemplates
those wheel supports 100 in which alternative structure is used to
provide sufficient support for spring biasing loads imposed upon
spring support 156, including by way of example only, increased
thickness for spring support 156, stiffening ribs attached or
incorporated into spring support 156, V-shaped and I-shaped
structural members, and various other equivalents known to those of
ordinary skill in the art.
[0077] FIG. 8B depicts a side elevational view of an embodiment of
wheel support 100 capable of supporting two wheels. A doubler plate
167 is installed on upright section 112 between section 112 and
wheel spindle 114. Doubler plate 167 provides an improved
distribution of load from spindle 114 within upright section 112.
In one embodiment of the present invention, upright section 112 is
constructed from A-36 steel plate of about one and one quarter inch
thickness. Doubler plate 167 is constructed from A-36 steel plate
of approximately one half inch thickness. In other embodiments the
doubler may not be needed, upright portion 112 being fabricated
from thicker material or higher strength material, incorporating
reinforcing ribs, or otherwise suitably strengthened.
[0078] FIG. 9 is a perspective view of a wheel support according to
one embodiment of the present invention. Wheel support 100 includes
a generally horizontal portion 168 attached to upright portion 112.
Horizontal portion 168 includes spring support 156 for supporting
air spring 133. In one embodiment, spring support 156 includes a
fastener pattern 174 for fastening air spring 133 to wheel support
100. However, in some embodiments of the present invention spring
support 156 is not fastened to air spring 133. Horizontal portion
168 also preferably includes a slot 176 or other means to provide
clearance for an air line for pressurizing and depressurizing air
spring 133. In some embodiments, the center of air spring 133 is
located between the rotational axis of the wheel and the pivotal
axis of the wheel support, as best seen in FIG. 4.
[0079] Referring again to FIG. 9, a reinforcing member 170, which
may include one or more distinct pieces, has a generally square
cross-section in one embodiment and supports some of the edges of
spring support 156. A reinforcing member 171 with a C-shaped
cross-section is attached to one end of reinforcement member 170
and also to upright portion 112. Reinforcement member 171 includes
a pair of inboard pivotal attachment members 180 and a pair of
outboard pivotal attachment members 178. Inboard attachment members
180 define holes 181 for coupling to second pivotal attachment 108.
Outboard pivotal attachment members 178 preferably define threaded
holes 179 for fastening to first pivotal attachment 110. In one
embodiment, holes 179 are oriented about ninety degrees from holes
181.
[0080] Multiple corner reinforcements 172a and 172b attach
reinforcement member 170 to upright portion 112 in one corner. A
corner reinforcement 172a similarly attaches member 171 to upright
portion 112. A reinforcement plate 173 is fused to one end of
reinforcement member 171 near upright portion 112 so as to better
distribute stresses within support 100. Plate member 173 and corner
reinforcement 172a enhance the stiffness and strength of the load
path from spindle 114 to outboard pivotal attachment members 180.
In one embodiment of the present invention, the included angle 175
from upright section 112 to spring support 156 is about ninety and
three fourths degrees, so as to provide about three fourths of a
degree of positive camber when not loaded by the weight of the
vehicle. Although a specific arrangement of reinforcement members
has been shown and described for wheel support 100, those of
ordinary skill in the art will recognize equivalent methods of
providing sufficient strength and stiffness.
[0081] FIGS. 10A and 10B depict side elevational views of pivotal
attachments according to one embodiment of the present invention.
Pivotal attachments 108 and 110 include pivotal inner support
member 108a and 110a, respectively, that are supported from
stationary outer members 108c and 110c, respectively, by
elastomeric bushings 108b and 110b, respectively. Inner supports
108a and 110a are able to pivot about pivot axes 109 and 111,
respectively. Inner pivotal member 108a includes a pair of through
holes 108d for coupling attachment assembly 108 by fasteners to
attachment members 180 of wheel support 100. In one embodiment
fastener holes 108d are oriented such that their centerlines are
inclined from the horizontal as indicated by angle 188. Fastener
holes 110d of pivotal inner member 110a, likewise used for
fastening pivotal attachment 110 to attachment members 178 of
support 100, are inclined from vertical in one embodiment as
indicated by angle 188. In one embodiment of the present invention
angle 188 is about seven and one half degrees, and may be as large
as about fifteen degrees. The offset angle 188 of the pivotal
attachments preferably corresponds to a similar offset angle for
wheel support 100 prime, as seen in FIG. 4, as will be discussed
later. In other embodiments, angle 188 is about zero degrees.
[0082] Although what has been shown and described are pivotal
attachment assemblies in which an inner pivoting member is
elastomericly mounted to an outer housing, the present invention
contemplates other type of pivotal attachment assemblies. By way of
example only, the present invention also contemplates pivotal
attachment assemblies in which a pivotal inner member is coupled by
a bearing, such as a ball bearing or plane bearing, to an outer
casing. By further way of example, the outer casing may be a cast,
molded, adhered, welded, or otherwise fixedly attached member to
the transverse frame section 116. By further way of example, the
inner pivoting member may be cast, molded, adhered, welded, or
otherwise fixedly attached or otherwise made integral with wheel
support 100, thus eliminating the need for attachment members such
as members 180 and 178. Yet other varieties of pivotal attachments
are known to those of ordinary skill on the art. It is preferable
that the pivotal attachments include a feature that permits spacing
apart of the pivotal attachment from either frame section 116 or
wheel support 110 so as to permit adjustment of wheel camber and
toe-in. One embodiment of the present invention which includes such
adjustment features will now be described.
[0083] Pivotal attachments 108 and 110 are preferably attached by
readily removable fasteners 177 to cross member 106, as seen in
FIG. 11. Pivotal attachment 110 supports the outboard side of wheel
support 100 via outboard pivotal attachment members 178. Pivotal
attachment 108 supports the inboard side of wheel support 100
through L-shaped inboard pivotal attachment members 180. Pivotal
attachment members 178 and 180 are preferably welded or otherwise
attached, cast, or molded within channel member 171 of wheel
support 100, as best seen in FIGS. 8A and 9.
[0084] Referring again to FIG. 11, pivotal attachment 110 is
capable of being spaced apart from cross member 106 of frame 116 so
as to move pivot axis 111 in a longitudinal direction relative to
the vehicle. This spacing may be accomplished, for example, by
insertion of a shim between pivotal attachment 110 and cross member
106. In addition, wheel support 100 may be spaced apart from
pivotal attachment 110 by insertion of shims between attachment
members 180 and pivotal inner member 110a. By spacing apart
attachment assembly 110 from frame 116, and/or spacing apart wheel
support 100 from attachment assembly 110a, the toe-in of the
supported wheel 102 can be adjusted.
[0085] Second pivotal attachment 108 is similarly coupled to cross
member 106 of frame 116, and may be spaced apart from frame 116 so
as to move pivot axis 109 longitudinally relative to the vehicle.
Thus spacing apart pivotal attachment 108 from frame 116 adjusts
the toe-in of the wheel 102 supported by support 100. In one
embodiment the present invention contemplates the use of shims for
adjusting both camber and toe-in, including shims fabricated from
sheet or plate material, and also shims in which the shim faces are
not parallel, but are angled in proportion to the desired toe-in or
camber angle. Further, the pivotal attachments are releaseably
coupled to the transverse frame section and also to the wheel
support so that the shimming may be performed easily and
repeatedly, as desired, without the need, for example, to remove
welded attachments.
[0086] Fastener attachment holes 108d are positioned about ninety
degrees relative to fastener holes 110d. Also, fastener holes 181
of inboard attachment members 180 are oriented about ninety degrees
relative to fastener holes 179 of outboard attachment members 178,
as best seen in FIG. 9. As a result, spacing apart inner pivotal
member 108a from attachment members 180 moves wheel support 100 in
a different direction than that achieved by shimming between inner
member 110a and attachment members 178. Spacing apart inner pivot
108a from attachment members 180 adjusts the camber of the wheel
102 supported by wheel support 100.
[0087] Although what has been described is an embodiment which
includes a pivotal attachment 108 which can be shimmed or otherwise
manipulated so as to adjust camber or toe-in and another pivotal
attachment 110 which can be manipulated to adjust toe-in, the
present invention also contemplates those embodiments in which
there are two pivotal attachments each permitting adjustment of
camber or toe-in or two pivotal attachments each permitting
adjustment of only camber or toe-in. Further the present invention
also contemplates embodiments in which neither pivotal attachment
permits adjustment of either camber or toe-in, or in which only one
pivotal attachment permits adjustment of either camber or
toe-in.
[0088] In one embodiment of the present invention, spring support
156 of wheel support 100 is preferably inclined from the horizontal
for improved airbag characteristics, as indicated by angle 188 of
FIG. 4. Wheel support 100x is shown in the inclined position during
operation of frame and suspension section 98 on a level surface.
The tire rotatably supported from wheel support 100y is shown at
full jounce over an irregularity in the roadway such that wheel
support 100y has pitched up and second spring support 156y is
generally parallel to first spring support 132y and also to roadway
190.
[0089] In this embodiment pivotal attachments 108 and 110 include
inner pivoting members 108a and 110a, respectively, which have an
included angle 188, as best seen in FIGS. 10A and 10B. By
incorporating an offset angle 188 into pivotal attachments 108 and
110 that is the same as the offset angle 188 of wheel support 100
prime, stress within elastomeric bushing 108b and 110b is kept to a
minimum during normal operation. Other embodiments of pivotal
attachments incorporating by way of example plane, roller, or ball
bearings in place of the elastomeric bushings would not need an
offset angle 188. The present invention also contemplates pivotal
attachments 110 and 108 in which the offset angle of the pivotal
attachments is different than the offset angle of the wheel support
relative to the roadway during normal operation, with the
difference in the pivotal attachment offset angle and the wheel
support offset angle being provided by angled attachment faces to
attachment members 180 and 178.
[0090] One embodiment of the present invention contemplates an
angle 188 of about 7.5 degrees between first spring support 132 and
second spring support 156 during typical operation of the
suspension system on a level roadway 190. Having an included angle
188 of about 7.5 degrees provides an acceptable range of air spring
characteristics and internal air pressure in one embodiment, and
permits placement of certain types of air springs below the cargo
compartment of the vehicle. However, the present invention
contemplates a range for angle 188 from about 0 degrees to about 15
degrees. For example, a cast wheel support with different
dimensions provides equally acceptable air spring characteristics
and internal pressure with an angle 188 of about zero degrees, such
that faces 154a and 154b of air spring 133 are generally parallel
during operation of the suspension on a level road.
[0091] In another embodiment of the present invention, there is a
suspension control system for maintaining the ride height of the
vehicle as the weight of the vehicle changes, and also for changing
the air pressure in the air spring in response to pivoting of the
wheel support. A linkage (not shown) attached to both wheel support
100 and the upright frame structure provides a control input to a
pneumatic valve (not shown), such as a Neway Model 9005-4007
leveling valve. In response to movement of the linkage, the valve
places air spring 133 in fluid communication with either ambient
air or with a source of air pressure such as air tank 192, which is
provided pressurized air from an air compressor. Movement of wheel
support 100 relative to the vehicle frame causes the valve to
increase or decrease the air pressure in air spring 133. The
control system adjusts the air pressure within air spring 133 so as
to maintain the wheel support at a predetermined angle relative to
the vehicle frame, and also to maintain a predetermined orientation
of the vehicle.
[0092] Although FIGS. 4, 5 and 6A depict an embodiment of the
present invention which includes six wheel supports 100 supporting
six wheels 102, some embodiments of the present invention include a
single wheel support 100 supporting a single wheel 102. Other
embodiments of the present invention, such as frame and suspension
section 98' shown as part of a van vehicle 200 in FIG. 12, include
two wheel supports 100 each supporting a single wheel 102. In yet
another embodiment of the present invention shown in FIG. 13, a
frame and suspension section 98" including four wheel supports 100
supporting four wheels 102 is shown in a trailer section of a
vehicle 202. Further, some other embodiments of the present
invention include a wheel support 100 that support a pair of wheels
102 to maintain adequate load margin in the tires when supporting a
heavy cargo load.
[0093] The frame and suspension sections shown herein may be built
modularly and slidingly coupled to a cargo compartment. As shown in
FIG. 6B, some embodiments of frame and suspension section 98
include a pair of rails 117 coupled to upright frame structures 122
and 124. These rails 117 slidingly engage a pair of receiving
C-channels 119 arranged on the underside of the trailer section of
vehicle 202. After the sliding insertion, the floor of the trailer
section is below the rotational axes of the wheels, the C-channel
of longitudinal member 150 being replaced with an L-angle
longitudinal member. The coupling of rails 117 and C-channels 119
limits lateral and vertical motion of the frame and suspension
section relative to the cargo compartment. A locking arrangement
(not shown) such as a plurality of locking shear pins inserted
through matched holes limits fore and aft relative movement.
Although a particular arrangement has been shown for coupling a
frame and suspension section of the present invention to a trailer,
those of ordinary skill in the art will recognize other
arrangements, including those in which the frame and suspension
section and trailer are not slidingly coupled.
[0094] FIGS. 14-16 depict another embodiment of the present
invention in which the shock absorber is located below the
rotational axis of the wheel. A wheel support 100' includes a
horizontal portion 168' coupled to an upright section 112'.
Horizontal portion 168' includes a spring support 156' receiving
and coupling to a spring which urges wheel support 100 away from
transverse frame structure 116. The use of (') and (") indicate
elements of the invention substantially the same as previously
described for that element, except for the changes as noted.
[0095] FIGS. 14-15 depict an embodiment in which a leaf spring 70
urges a pair of wheel supports 100' from transverse frame structure
116. Leaf spring 70 includes a first end 70a clamped by a pair of
bolts to spring support 156'. A second end 70b is in sliding
contact with spring support 156' of the aft-most wheel support.
Ends 70a and 70b are located between their respective second spring
support 156' and the rotational axis of the wheel. The center 70c
of leaf spring 70 is fastened to a portion of cross-member 106 of
transverse frame structure 116 which is the frame spring support.
Pitching movement of either the forward-most wheel support 100' or
the aft-most wheel support 100' is resisted by a biasing force from
the center of the leaf spring.
[0096] Although a particular arrangement for contacting leaf spring
70 with wheel supports 100 and transverse frame structure 116 has
been shown and described, those of ordinary skill in the art will
recognize other suitable arrangements. For example, both ends of
spring 70 could be clamped to the wheel supports, or both ends
could be slidable on the wheel support. Further, the method of
clamping leaf spring 70 can be one or more through fasteners, an
example of which is depicted at 70c, or a fastened strap, as
depicted at 70a, or other methods known in the art for clamping a
leaf spring to a structure. As another example, spring 70 can pass
through a frame attachment 74 as shown in FIG. 1. Further, although
FIG. 14 depicts a leaf spring 70 acting upon two adjacent wheel
supports, the present invention also contemplates those embodiments
in which a leaf spring acts upon a single wheel support. As
depicted in FIG. 16, an alternate embodiment includes an air spring
133 acting on both spring support 156' of wheel support 100' and
also on spring support 132' of transverse frame structure 116.
[0097] Referring to FIGS. 14-15, shock absorber 136 is located
beneath the rotational axis of the wheel so as to further simplify
the structure of the wheel support, upright frame structures 122
and 124, and to further increase the cargo-carrying capability of
the vehicle. Placement of shock absorber 136 is such that it acts
upon horizontal portion 168' at wheel support 100', and permits
elimination of support structure 134 and a generally simplified
upright structure 112'. Shock absorber 136 is actuatable about an
axis 137a, which is generally oriented horizontally as best seen in
FIG. 15.
[0098] Shock absorber 136 has a first end 136a which is pivotally
coupled to a portion of transverse frame structure 116, such as
cross-member 106 or longitudinal member 126', through an attachment
ear 140. A second end 136b of shock absorber 136 is pivotally
attached to one end of a lever arm 222. Lever arm 222 is pivotally
secured to pivot 224 which is attached to transverse frame
structure 116, such as by a bracket 226 in a manner well known in
the art. Lever arm 222 pivots about pivot axis 221. The other end
of lever arm 222 defines a slot 228. Pinned bushing 229 is slidable
in slot 228. Pinned bushing 229 is secured into a boss 220 of wheel
support 100'.
[0099] Upward pitching of wheel support 100' results in compression
of shock absorber 136 and sliding of pin 229 within slot 228.
Downward pitching of wheel support 100' relative to transverse
frame section 116 results in extension of shock absorber 136.
Pinned bushing 229 and lever arm 222 are fabricated from hardened
steel so as to minimize wear from sliding. Further, although an
embodiment has been described and depicted in which shock absorber
136 compresses during upward pitching of wheel support 100', those
of ordinary skill in the art will recognize other arrangements of
pivoting lever arms that will suitably dampen the motion of wheel
support 100' by extending during upward pitching.
[0100] FIGS. 17-18 depict a substantially cast wheel support 100"
according to another embodiment of the present invention. Wheel
support 100" includes a horizontal portion 168" cast integrally
with an upright portion 112". A spring support 156" within
horizontal portion 168" receives loads from a spring, and is
reinforced by a plurality of cast stiffening ribs 169". A cast
reinforcing member 170" stiffens and strengthens wheel support
100". Attachment members 178" and 180" are cast integrally with
wheel support 100".
[0101] A support structure 134" for attaching a shock absorber and
brake system components is integrally cast with upright portion
112". Upright portion 112" also includes a cast spider 239 which
includes an attachment pattern of holes 240, 242, and 244 for
support of brake system components (not shown) including brake
shoes and an S-cam. The toe-in of wheel support 100" is adjustable
by shimming in a manner as previously described. Camber is
adjustable by incorporating slots in stationary outer members 108c
and/or 110c of the pivotal attachments. The slots permit the
orientation of outer member 108c or 110c to be adjusted relative to
cross-member 106. This orientation is maintained by a friction fit
provided by fasteners 177.
[0102] Yet other alternate embodiments of the present invention
include a wheel support and a disc brake as part of a wheel
suspension system. As shown in FIG. 19, an upright section 112' is
bolted to a spindle 114 by fasteners through fastener attachment
pattern 160. A rotating hub 162 is bearingly supported on spindle
114. Coupled to hub 162 is a vented disc assembly 165 comprised of
opposing rotor plates 165a and 165b. A caliper assembly 159
supported by upright portion 112' includes two friction pads 161
which are actuated against vented disc 165 so as to slow the
vehicle. For sake of clarity, only one friction pad 161 is shown.
Those of ordinary skill in the art will recognize the applicability
of disc brakes to the many embodiments of the present
invention.
[0103] FIGS. 20, 21 and 22 depict variations of the suspension
systems shown in FIGS. 3, 5 and 14, respectively, in which the
wheels on one side of the vehicle are longitudinally staggered, or
spaced apart, relative to wheels on the other side of the vehicle.
By staggering the wheels as shown, a softer ride can be presented
to the cargo or occupants, and less wear is imposed upon the
roadway, especially a roadway with a disturbance that passes under
the wheels on both sides of the vehicle
[0104] In the embodiments depicted in FIGS. 20 and 22 wheel
supports on a given side of the vehicle (same-side wheel supports)
include one or more springs that couple the forward wheel support
to the aft wheel support. In these embodiments, the motion of a
same-side wheel support thereby depends, at least partly, on the
motion of the other same-side wheel support. However, the present
invention also includes embodiments such as the one depicted in
FIG. 21, in which the motion of each wheel support is substantially
independent of the motion of each other wheel support.
[0105] In some embodiments of the present invention, the extent of
stagger between opposite side wheels is as great as half the
distance between rotational axes of same-side wheels. However, the
present invention also includes those embodiments in which the
extent of stagger is less.
[0106] In the embodiments depicted in FIGS. 20-22, an even total
number of rotational axes are arranged on both sides of the vehicle
in an alternating longitudinal pattern, with no rotational axis
being coincident with any other rotational axis. However, those of
ordinary skill in the art will recognize that the present invention
contemplates not only embodiments in which there is a forward-most
wheel on the right side of the vehicle with an aft-most wheel on
the left side, but also embodiments in which the forward-most wheel
is located on the left side and the aft-most wheel is located on
the right side. Further, the present invention also contemplates
those embodiments in which both the forward-most and aft-most
wheels are on the same side of the vehicle, and also those
embodiments in which one side of the vehicle has an even number of
wheels and the other side of the vehicle has an odd number of
wheels, such as by way of example, a vehicle with two wheels on one
side and one wheel on the other side. Further, the total number of
rotational axes per frame section is as low as two, and is as great
as required in the particular application.
[0107] The use of element numbers the same as numbers previously
used, including element numbers with letter suffixes, indicates
that the element referred to is the same, except as described.
[0108] FIG. 20 depicts an embodiment of the present invention to
which the discussion herein relative to FIGS. 1, 2 and 3 is
applicable, except as now described. Although a description of the
"a" side components is given, those of ordinary skill in the art
will recognize applicability of the description to the "b" side
components. Frame and suspension section 398 of a vehicle frame
includes a forward-most wheel 8a and a rear-most wheel 10a located
on one side of the vehicle frame. Wheels 8a and 10a are pivotally
supported by wheel supports 24a and 26a, respectively, in a manner
as previously described. Wheel supports 24a and 26a are coupled
together by a leaf spring 70a, also in a manner as previously
described. Further, biasing members 50a, 56a and 60a are located
generally above the rotational axes of the wheels, also as
previously described.
[0109] The rotational axes 12a and 14a of wheels 8a and 10a,
respectively, are staggered, or longitudinally spaced apart, from
the rotational axes 12b and 14b of wheels 8b and 10b, respectively.
In one embodiment, the four rotational axes are arranged in an
alternating longitudinal pattern, with no rotational axis being
coincident with any other rotational axis. Rotational axis 12a is
located in this embodiment aft of rotational axis 12b, and forward
of rotational axis 14b. Rotational axis 14a is located aft of all
other rotational axes.
[0110] FIG. 21 depicts an embodiment of the present invention to
which the description herein relative to FIG. 5 and related figures
is applicable, except as now described. Although a description of
the "e" components is given, those of ordinary skill in the art
will recognize applicability of the description to the "a," "b,"
"c," "d," and "f," components. As previously described, frame and
suspension section 498 of a vehicle frame includes a wheel 102e and
tire 104e rotatably supported by a spindle 114e coupled to a wheel
support 100e. The wheel support is pivotally attached to frame
section 498 by pivotal attachments 108e and 110e. An air spring
133e biases wheel support 100e and wheel 102e to a position
intermediate of an uppermost position and a lowermost position. An
optional shock absorber 136e for dampening motion of wheel 102e is
pivotally coupled to both wheel support 100e and frame structure
416. The rotational axes 158a, 158c, and 158e, of wheels 104a,
104c, and 104e, respectively, are staggered, or longitudinally
spaced apart, from the rotational axes 158b, 158d, and 158f, of
wheels 104b, 104d, and 104f, respectively. The present invention
also contemplates patterns of stagger other than that shown in FIG.
21, for example, including an asymmetric pattern in which
rotational axis 158b is located forward of rotational axis 158a, or
in which rotational axis 158e is located aft of rotational axis
158f.
[0111] FIG. 22 depicts an embodiment of the present invention that
is the same as the embodiments described herein relative to FIGS.
14, 15 and 16, except as now described. Although a description of
the forward-most "b" components is given, those of ordinary skill
in the art will recognize applicability of the description to the
"a," "c," and "d," components. Further, although an embodiment with
a leaf spring linking adjacent, same-side wheel supports is shown,
those of ordinary skill in the art will recognize that the present
invention also includes the embodiments depicted in FIG. 16, which
include an air spring.
[0112] As shown in FIG. 22, a wheel set comprising a pair of wheels
104b' and 104b" rotatable about an axis 158b are supported by a
wheel support 100b' pivotally attached to frame structure 516 by
pivotal attachments 108b and 110b. The pitching movement of wheel
support 100b' is dampened by shock absorber 136b, which is
pivotally coupled to both frame section 516 and wheel support
100b'. Shock absorber 136b is substantially horizontal.
[0113] The rotational axes 158b and 158d of wheels 104b' and 140d',
respectively, are staggered, or longitudinally spaced apart, from
the rotational axes 158a and 158c of wheels 104a' and 104c'. As
shown, the four rotational axes are arranged in an alternating or
longitudinally spaced apart pattern, with no rotational axis of any
one wheel set being coincident with the rotational axis of any
other wheel set. Those of ordinary skill in the art will recognize
that the present invention also contemplates those embodiments in
which only wheel sets "a," "b," and "d," are present.
[0114] FIG. 23 depicts an embodiment of the present invention that
is the same as the embodiments described herein relative to FIGS.
14, 15 and 16, except as now described. The wheel support described
herein may be pivotally attached to a frame as trailing-arm wheel
supports, in which the pivotal attachment of the wheel support to
the frame is located forward of the rotational axis of the wheel,
or as leading-arm wheel supports, in which the pivotal attachment
of the wheel support to the frame is located rearward of the
rotational axis of the wheel.
[0115] As seen in FIG. 23, a first wheel support 100'a rotatably
supporting a wheel 104a on a first side of frame 516 has inboard
pivotal attachment 108 and outboard pivotal attachment 110 located
forward of rotational axis 158a. A spring, preferably an air spring
133a, urges first wheel support 100'a apart from a portion of frame
516. An end of air spring 133a is coupled to frame 516 below
rotational axis 158a.
[0116] A second wheel 104b is pivotally supported by a second wheel
support 100'b on the other side of frame 516 in a manner similar to
that for the "a" components described above. However, inboard
pivotal attachment 108 and outboard pivotal attachment 110 of wheel
support 100'b are placed rearward of rotational axis 158b. By this
arrangement of a trailing arm wheel support 100'a on one side of
the frame and a leading-arm wheel support 100'b on the other side,
it is possible to use an identical wheel support for opposing sides
of the vehicle, and thus benefit from a reduction in cost of the
frame and suspension section 698, and also a reduction in the
number of different parts for building a frame and suspension
section 698.
[0117] The present invention also contemplates those embodiments in
which other combinations of leading and trailing wheel supports are
utilized on a frame and suspension section. Wheels 104a and 104c
are shown supported by wheel supports 100'a and 100'c,
respectively, both wheel supports being pivotally supported by a
common portion of frame 616. Other embodiments of the present
invention include wheel supports arranged as shown in FIG. 23 with
wheels 104b and 104d. Those wheels, supported by wheel supports
100'b and 100'd, respectively, may be placed close together by
arranging the pivot axes of the respective wheel supports as shown.
Those of ordinary skill in the art will recognize that frame and
suspension section 698 as shown in FIG. 23 is but one arrangement
combining leading and trailing wheel supports, and that many other
arrangements are contemplated by the present invention.
[0118] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character, it
being understood that only the preferred embodiments have been
shown and described and that all changes and modifications that
come within the spirit of the invention are desired to be
protected.
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